The present invention generally relates to a storing unit, and more particularly, to a tape cassette storage rack for use, for example, in a video tape recorder (VTR) automatic tape feeding apparatus which is arranged to automatically feed the tape cassettes, accommodated in tape cassette storage racks, with robot equipment.
Recently, the VTR automatic tape feeding apparatus as referred to above, and capable of accommodating a large number of tape cassettes therein, has come to be widely utilized in the automatic broadcasting of news, commercials or regular programs by a broadcasting station, and also, as automatic video image servicing machine in a cultural center, museum, library or the like.
Conventional VTR automatic tape feeding apparatuses of the above-described type are disclosed, for example, in U.S. Pat. Nos. 3,839,197 and 3,938,190, and various methods for storing tape cassettes have also been proposed.
Referring to FIGS. 1 to 3, one example of a conventional tape cassette storage racks will be described hereinbelow.
In FIG. 1, the known tape cassette storage rack includes a rack main body 10 having an elongated opening 11 at its front portion for allowing a tape cassette (FIGS. 2 and 3) to be mounted or dismounted therethrough, side walls 12 extending upwardly from opposite sides of the rack main body 10, with a distance therebetween corresponding to a width of a tape cassette of a standard size (a standardsized tape cassette 1a in FIG. 2, which will be referred to as a standard tape cassette), a bottom plate 13 formed with a protrusion 14 having, for example, a rectangular cross section to be fitted into a groove of a similar cross section provided at the bottom of the tape cassette, and a rear wall 15.
The bottom plate 13, side walls 12 and rear wall 15 of the rack main body 10 are integrally formed of a resin material so as to define a space for accommodating the tape cassette therein. Moreover, on the side walls 12, there are fixedly attached plate springs 16 each projecting into the tape cassette accommodating space referred to above by 2 to 3 mm and having a shape engageable with recesses, or grooves 2 (FIGS. 2 and 3) of a V-shaped or U-shaped cross section formed in corresponding side walls of the tape cassette.
In FIG. 2, showing the state where the standard tape cassette 1a is inserted in the storage rack, said tape cassette 1a is guided by the protrusion 14 formed on the bottom plate 13 of the rack main body 10, and also by the side walls 12 of said main body, while its back and forth movement (i.e. movement in a direction to insert or withdraw the tape cassette) is restricted by the plate springs 16 on the opposite side walls 12 which engage the grooves 2 formed on the side faces of said tape cassette 1a.
FIG. 3 shows the state where a small tape cassette 1b is inserted in the storage rack of FIG. 1. The bottom of the small tape cassette lb defines a groove having a rectangular cross section (not particularly shown) for receiving the protrusion 14 on the bottom plate 13 of the storage rack. The groove is located at the same distance from one side wall of the cassette as in the standard tape cassette 1a. Thus, the small tape cassette 1b is guided by the protrusion 14 and one side wall 12 of the storage rack, with the plate spring 16 at one side of the rack being engaged with the groove 2 formed on the side face of the cassette 1b for restricting the back and forth movement of said tape cassette 1b in a manner similar to that in the tape cassette 1a.
FIG. 4 shows the state where a large number of storage rack main bodies 10 as described above are piled up in many stages, whereby movement of the tape cassettes 1a in an upward direction is restricted. In the above arrangement, the tape cassettes 1a, the plate springs 16 of the storage rack are to be pushed open, while when inserting the tape cassette 1a, the tape cassette 1a pushes open the plate springs 16, with said plate springs 16 ultimately engaged with the grooves 2 of the tape cassette 1a as described earlier.
The withdrawal and insertion of the small tape cassette 1b can be effected in a similar manner by utilizing the protrusion 14 and the plate spring 16 at one side wall 12, and thus, the storage rack is capable of positioning two kinds of tape cassettes of different sizes at the predetermined position.
However, the known arrangement as described so far has the following disadvantages.
Namely, in cases where the tape cassettes are to be manually (i.e. by human hand exchanged with those outside the VTR automatic tape feeding apparatus due to the expiration of the tape life or to merely effect a desired alteration of the contents of the tape to be supplied, or in cases where they are to be manually replaced due to urgent requirements in a broadcasting station, when such tape cassettes are taken out from the state in which they are accommodated in the piled up storage racks, it is required to provide gaps for inserting fingers between the described tape cassette to be taken out and the tape cassettes accommodated in positions above and below said desired tape cassette, thus necessitating a reduction in area efficiency. Meanwhile, it becomes very inconvenient if it is intended to deal with the problem through the reduction of the gaps or by employing a tape withdrawal jig or the like.